1. Field of the Invention
The present invention relates to transparent/translucent blocks as building materials used in commercial and residential construction and, more particularly, to ventilated interlocking blocks of manmade materials.
2. Description of Related Art
For decades, hollow glass blocks have been used to form interior or exterior walls or sections thereof in order to permit transmission of light through such walls. Usually, these glass blocks distort any images viewed therethrough or the blocks may be translucent to permit passage of light and yet provide a significant degree of privacy. For example, glass blocks have been used as part of a bathroom wall to permit transmission of light therethrough, particularly important if there are no windows in the bathroom, and yet provide privacy. In a commercial or private environment, walls or wall dividers have been formed of translucent hollow glass blocks to delineate floor space while accommodating light transmission therethrough to create a more airy and open environment without compromising privacy.
Hollow glass blocks serve the sought end result very well but several difficulties are created. First, the glass blocks are relatively heavy and generally are only permitted to be used under building codes in conjunction with supporting brick walls; conventional wood frame construction is generally considered of insufficient structural strength to support glass blocks. Second, transport of the glass blocks from a point of manufacturer to the end user is generally expensive because of the weight and the attendant crating and shipping costs. Third, in order to accommodate the change in pressure within the hollow part of the glass block due to temperature and elevational changes, the glass walls must be very thick. Fourth, assembling a wall or wall section of glass blocks requires a skilled artesian to properly align the glass blocks and to exercise skill in securing the glass blocks to one another with a binding agent.
To overcome the weight and handling difficulties attendant hollow glass blocks, hollow blocks of transparent/translucent manmade materials have been developed; hereinafter referred to as plastic blocks. These plastic blocks generally include interlocking elements to permit seating and rapid assembly. In some circumstances, depending upon the configuration and use of the plastic block, a binding agent must be used. The primary benefits of plastic blocks include light weight, ease of handling and installation, and relatively low cost.
The plastic blocks are hollow and the interior space is sealed against intrusion of foreign matter as well as air. In response to temperature changes or changes in elevation (primarily during shipping), the pressure within the plastic blocks increases and decreases proportionately. The pressure changes within the plastic blocks generally result in inward or outward flexing of the walls of the plastic block. Such flexing creates stresses within the plastic material. During cleaning with conventional cleaning agents, lines of stress become visually apparent. The resulting disfiguration becomes permanent and compromises the aesthetics of the wall or wall section formed of the plastic blocks.